1. Technical Field
The invention relates to an electronic apparatus. Particularly, the invention relates to a load apparatus for testing a light emitting diode (LED) driving circuit.
2. Related Art
Since light emitting diode (LED) has advantages of low power consumption, long service life, environmental protection and small size, etc., it is widely used in backlight modules of illumination equipment, various display equipment and various mobile electronic products. However, since physical characteristics of the LED are unique, and the LED has a so-called light declining problem after a period of use time. Therefore, a current LED driving circuit generally drives the LED through a constant current mode. In order to test whether the LED driving circuit normally operates, following methods are generally used to implement the test. A first method is to directly use an actual resistor to serve as a load of the LED driving circuit, though since an impedance characteristic of the LED is not completely the same to a linear impedance characteristic of a general resistor, an obtained testing result is not necessarily suitable for actually driving the LED. A second method is to directly use an LED light bar (i.e. a plurality of LEDs connected in series) to implement the test, if the LED driving circuit is unstable, the LED serving as the load is often burned to increase the testing cost, and different numbers and specifications of the LEDs have to be prepared for different LED driving circuits to implement the test. A third method is to use a “programmable electronic load” dedicated to the simulation test to implement testing the LED driving circuit. However, the price of the programmable electronic load dedicated for experiment and simulation is too expensive, which is a heavy burden to the manufacturer in case of extensive production testing. Therefore, an applicable and convenient testing technique is required for testing the LED driving circuit.